Carl Sagan talks about this point in Cosmos. Life arose here on Earth pretty quickly after it cooled. So the thought is that it's not difficult for life to appear on favorable, habitable planets. A probability of 0.1% may be far too low.
Remember too, an earth-like planet can have lots of organic chemicals floating around, and you only have to hit the right combination once over millions of years to end up with life.
Remember too, an earth-like planet can have lots of organic chemicals floating around, and you only have to hit the right combination once over millions of years to end up with life.